'Solar Ready' definition

[TyCreek]

Since you're sort of on the edge of things with your thoughts ... those are tough questions to answer. A purely safety guess would be that you might be "ok" with high quality 18V PVs depending on the length of the 10 gauge wire. Assuming that's the wire gauge in your pre-wire... A 330W PV array is theoretically embarking on quite usable mild RV power generation that nets more like 250W at peak mid day operation.

Swapping to a 2000W inverter for the sake of pure sine is a logical idea if you never pull more than the original 1000W circuit design. Consider a 1000W inverter load to be about 100A draw (consider efficiencies) from your factory 12V battery source. So, the capability will almost certainly be there for unsafe AC operating conditions.

A well designed system can last many years if it factors in efficiencies and safety at all points.

[David1912]

Thanks...my guess is the wire run length will be 15-20 ft...

Our idea is to run light electric devices...no fridge...for sure no AC. Might hope to be able to microwave a couple of times per day to re heat coffee. Tabs and charge devices... lightish boondocking ... may 1-3 days at a time

And in the future we would plan to upgrade batteries...so goal is to start w 360 panels, appropriate wiring, good controller and nice 2000 w true sine inverter so we can 'test drive', then possibly enhance with more panels and battery setup...thanks

[TyCreek]

I encourage those considering solar for their RV to do a lot of reading from sources other than those trying to sell you something. Forums are ok for some information however there's a LOT of misinformation to weed through. If possible talk to people that actually operate off-grid with their RVs more than a weekend here and there One thing I learned from this is that most fail miserably with their first solar venture.

I don't have many saved solar links for RVs but here's one that might be worth reading: RV Electrical

[David1912]

Thanks, I agree completely...am trying to do a lot of research. Have watched a lot of youtubes, joined a couple boondocking groups and talked to what I think is a credible installer... to be sure i am willing to pay for quality components, design and an install...with this said my working goal is to do my work in two stages (with no issues caused by doing it this way)

[scrubjaysnest]

We primarily dry camp most of the summer and sometimes Dec. and Jan. in AZ. Our current solar is 300 watts portable and I'll be adding 200 watts to the roof. The portable set up uses 25 feet of 8 awg marine grade wire and has been in service since 2012 on a previous TT and now our Axis.
With 12 volt dc systems voltage loss is the problem and the usual fix is larger wire.
We went with 3 100 watt panels for the portable system because it is easy to handle. At 2X3 feet 17 LB panels aren't heavy just awkward to handle.

Check here for general guide lines: RV Electrical
Just as detailed as HandyBob's blog but doesn't have the rant.

[Chance]

Originally Posted by scrubjaysnest

....cut....

Check here for general guide lines: RV Electrical
Just as detailed as HandyBob's blog but doesn't have the rant.

Interesting that he claims optimum solar panel voltage for a 12-Volt battery system should be in the 30 to 50 Volt range when using MPPT controller. If correct, it makes the Thor-provided wiring size from the roof look just fine (at least from my perspective). You'd have to go to a fairly large system before amperage would become an issue at those higher voltages. Just an observation.

[TyCreek]

It is a big win for 12V RV systems that controller options are becoming more capable of high voltage PVs driving lessor supplies! Also nice that Lithium charge profiles are becoming more common too

Next we need higher voltage power storage and system options in our RVs.

[sage]

Have you looked at the River Mobile Power Supply? This isn't quite what we need yet but it's getting there.

[Chance]

Originally Posted by TyCreek

It is a big win for 12V RV systems that controller options are becoming more capable of high voltage PVs driving lessor supplies! Also nice that Lithium charge profiles are becoming more common too

Next we need higher voltage power storage and system options in our RVs.

Since a large lithium-battery house system probably should not be charged from the vehicle's alternator, there is no reason I can see why a second stand-alone system couldn't be utilized today with whatever voltage was preferred. I'd personally pick 48 Volts since most of the energy will go to power a large inverter, and 48 Volts will most likely become the next standard DC voltage.

The overall system architecture could be very similar to what's being done to switch cars from 12 to 48 Volts. Large loads would be on 48-Volt side, with low energy users remaining on 12 Volts. The rest is just engineering details.

[scrubjaysnest]

Originally Posted by Chance

Interesting that he claims optimum solar panel voltage for a 12-Volt battery system should be in the 30 to 50 Volt range when using MPPT controller. If correct, it makes the Thor-provided wiring size from the roof look just fine (at least from my perspective). You'd have to go to a fairly large system before amperage would become an issue at those higher voltages. Just an observation.

Over on the solar-electric forums the suggested ratio is no more then 4 to 1.
So for a 12 volt battery that would be 48 volts.
If one is planning of PV panels with higher then 21 volts Voc then it really makes sense to go with MPPT; the same if wiring panels in series.
Series panels make sense out west with no shading but on the East coast or with shading parallel is better.

[Chance]

Originally Posted by scrubjaysnest

Over on the solar-electric forums the suggested ratio is no more then 4 to 1.
So for a 12 volt battery that would be 48 volts.
If one is planning of PV panels with higher then 21 volts Voc then it really makes sense to go with MPPT; the same if wiring panels in series.
Series panels make sense out west with no shading but on the East coast or with shading parallel is better.

Thanks, good to know.

I haven't looked into technical design details yet, in large part because we travel or tour more than camp in one place, so engine alternator can do all we need to keep batteries charged even if not on shore power.

I did see one 400-watt panel that's rated for 48 Volts nominal. I suppose they could be wired in parallel with the right controller if looking for large system. For us the economics just don't work out well, but that's changing constantly. In any case I'm glad Axis comes prewired. Since we keep vehicles so long, it's likely I'll end up with solar at some point -- even if just to keep battery charged while stored.

[Chance]

This is curve:

[w6lmj]

The date on the tech sheet is 11/07/16. Does that mean all 25.5 Axis Vegas have the wiring harness ready for solar?

[w6lmj]

Do a couple shorter trips first, if possible. I traded travel trailers in the middle of chasing dinosaur footprints across America. About 3k miles. The original tires on the new trailer failed at about the 900-mile range. A low-end trailer with poor axils and cheap tires. But the point is, gain experience before you put too much distance between you and your point of purchase. Interestingly enough, we found plenty of dinosaur tracks.

The best were found at Lake Clayton, in northeast New Mexico. The deepest near Dead Horse Point, State Park, Utah. Those were deep enough that we could photograph the youngest grandkid sitting waist deep in the footprint of a sauropod.

[w6lmj]

I thought I read someplace that the engine on the Mercedes Chassis does not charge the coach batteries? They only charge from the shore power or the generator. Is that wrong?

[w6lmj]

This has been a great thread.

I am waiting on the delivery of a Thor Citation on a Mercedes chassis and wondered about "solar ready", too. I wonder if solar ready means I can connect a solar panel or two?

Should I expect to be able to connect 100 watts, 200 watts...?

How about the battery charger and inverter? Should I expect to buy a kit to ensure those things work with the solar panels? If it is solar ready, what does that save me in terms work I won't have to do because it is solar ready?

Maybe it means the electrical panel can accept power from a solar system without having to do an upgrade to a new coach?

How big in the inverter that comes standard? I have not been able to find that information.

I guess when I take delivery I should send them a list of questions I would like answered and give them a chance to have the answers.

[BASSMAN]

I have a general question for the group, what are some of you trying to power with your thoughts on a solar package? i bought a new 2017 Thor Axis 25.4, the two group 24 coach batteries are a joke, even with all the LED lights i have had dead batteries at the end of the day, I am looking at a 400 watt 4 panel system available from Amazon for around $600.00, but i am seeing posts on inverters for 2000 watts. gotta wonder what some are trying to run off a 2000 watt inverter, how many and what size battery and solar combo would it take to keep a 2000 watt inverter delivering out put?

[w6lmj]

I am trying to avoid running the generator or LP if I can use primarily solar and house batteries. I am thinking of 400-watt solar panels and lithium batteries. I want to make coffee and fix a light breakfast. I don't plan to run the microwave or the AC.

[DogLovers]

Gee I dunno people. I'm still a fan of a small nuclear reactor tucked under the tail. A small unit about the size of a deck of cards will provide enough juice to run your unit and perhaps 3-6 others as well. It could double as a tailgater eliminator. You know, when those pesky followers get right up on your tail, beeping weaving in and out of the lane because they can't wait to dart around you on a double yellow line curve going uphill to cause a wreck. You could simply eject the core (Star trek) so it would detonate under them sending them home. Just an idea.

[JamieGeek]

Originally Posted by DogLovers

Gee I dunno people. I'm still a fan of a small nuclear reactor tucked under the tail. A small unit about the size of a deck of cards will provide enough juice to run your unit and perhaps 3-6 others as well. It could double as a tailgater eliminator. You know, when those pesky followers get right up on your tail, beeping weaving in and out of the lane because they can't wait to dart around you on a double yellow line curve going uphill to cause a wreck. You could simply eject the core (Star trek) so it would detonate under them sending them home. Just an idea.

Don't need to go all sci fi: Just get an RTG from NASA (Radioisotope thermoelectric generator). These use the heat from decaying radioactive material to generate power. They are commonly found on space probes (yeah Pioneer, Voyager, and even Curiosity on Mars all have one--and one was a big plot point in The Martian).

You could still eject the core and cause major damage to whomever is following too closely

Of course we aren't making the material required for these anymore so one would be hard to find (even NASA has started to look for other power options).